Rapid antigen tests for COVID-19 are much less sensitive in asymptomatic persons (40% vs 80% in symptomatic persons)

How accurate are rapid antigen tests for COVID-19 in both asymptomatic and symptomatic patients?

A rapid antigen test (Sofia FIA from Quidel) was highly specific, but sensitivity was 80% in symptomatic patients and only 40% in asymptomatic patients. In asymptomatic patients, due to the low prevalence in this sample (2%), there was also a high false positive rate of 67%.